So if we find the intersection of zeros and poles in the retarded Green's functions, we can obtain these special points. We can use the simpler method, the AdS/CFT duality, to solve special points from bulk field equation [1]}, [2]}, [3]}, [4]}. On the bulk field side, there is no unique incoming mode at the horizon and is similar to the “pole-skipping” phenomenon in holographic chaos.
